Question

Question #048d7

Answer 1

Acceleration is not the same after impact

Explanation:

Picture the falling objects, one starting from a lower height and one starting from higher.

When both hit the ground, they will be going different speeds (the one that started higher will be going faster since it had more time to accelerate due to gravity).

Assuming the ground stops the two objects in the same amount of time (which is not precisely true, but we can approximate), then the one going faster will experience a greater acceleration while slowing down, and thus a greater force.

We know that `(\Delta v)/( \Delta t)=a`
(or use differentials if you know what those are, but don't worry about that if you don't)

So if `\Delta v` is larger in the same amount of time, the acceleration will be larger, and the force will be too.

I think your confusion here is coming from thinking about the objects when they're in free fall. In that case, the force IS the same, but once they hit the ground, it's a different story.

(also, it's important to note that all of this is assuming non-relativistic speeds and such, but I think for the sake of this problem that's an okay thing to assume)